Doug Gregor ae8e95d5d9 [Embedded] Introduce a test for @_implementationOnly + @_neverEmitIntoClient ...

In Desktop Swift, @_implementationOnly imports allow one to hide the
implementation so long as you're careful to only reference entities
from the imported modules in code that gets compiled into the object
file and *not* referenced by the corresponding Swift module file.

Until very recently, there was no such affordance for Embedded Swift,
because all functions would have their SIL serialized to the Swift
module file. Using them from a client module would then attempt to
deserialize the SIL, loading the @_implementationOnly-imported module
and causing the compiler to abort. With the introduction of
@_neverEmitIntoClient, we now have a way to say "only in the object
file, never in the module file" for the definition of functions.

Introduce a test that makes sure @_implementationOnly +
@_neverEmitIntoClient has the desired effect of hiding the imported
modules from clients. It's still brittle and hard to use, just like
the existing @_implementationOnly, but this shows that it's at least
possible to do this implementation hiding in Embedded Swift.

2025-08-19 16:03:18 -07:00

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CHeader.h

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module.modulemap

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SwiftDependency.swift

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